1. Field of the Invention
The present invention relates to the application of visually sharp and distinct patterns to composite articles during manufacture thereof and, more specifically, to the manufacture of sporting articles such as arrow shafts, golf shafts, baseball bats, hockey sticks, ski poles, archery stabilizers and bike tubing having surface patterns such as manufacturers' names and logos, etc. thereon.
2. Prior Art
The application of surface patterns to articles subject to surface wear, particularly target arrow shafts or the application of camouflage patterns to hunting arrow shafts, is ordinarily accomplished by surface painting of the article or by application of surface decals and artwork thereto. If the articles are made of metal having a somewhat porous metal oxide surface coating such as is produced by anodizing for example, surface patterns have been applied by face-to-face contact of the surface of the article with a pattern carrier on which patterns produced by sublimating ink or dye are provided. The sublimation process has not heretofore been applicable to the surface of articles made of composite materials such as carbon fiber reinforced epoxy resin since such articles first of all have a dark, almost black, surface coloration against which patterns of contrasting color, if applied, will not be particularly visible and, secondly, the surface of composite particles is non-porous and therefore non-absorbent and is thus unsuitable for application of patterns using a sublimation process.
Continuous formation of composite articles using pultrusion processes is well known for example from U.S. Pat. No. 5,122,417 issued Jun. 16, 1992 to Murakami, et al. As disclosed therein, products of circular and non-circular cross-sectional contours manufactured by impregnating fiber tows or rovings with a resin and drawing them into a die to form an article of predetermined size and shape is used to produce a variety of high-strength articles.